This invention relates generally to control or adjustment of window coverings, and more particularly to ease and efficiency of window covering height adjustment. Such window coverings are referred to as shades, or blinds, or window coverings generally, and may be formed by pleats of a single piece of material, or by other configuration.
There is need for improvements in adjustability of such coverings or shades, as for example where the effective window covering height of the shade is to be adjusted. In the past, pleated shades were suspended by their own material, i.e. were allowed to hang, causing the weight of the shade to expand the pleats. It was then difficult to accurately adjust shade height, since over time the shade weight could expand the pleats, changing the overall height of the shade. Such pleated shades typically consisted of paper. Also venetian blinds and all window coverings require raising and lowering functions.
It is a major object of the invention to provide an easily adjustable means allowing shade height adjustment, and where only a minimum number of shade supporting lines are required.
Basically, the improvement comprises
a) upper support structure at or proximate the shade top,
b) at least one substantially vertically elongated shade support line extending downwardly from said upper support structure,
c) shade lower support structure at or proximate the shade bottom, and shade adjustment includes:
d) elevating or lowering the shade lower support structure relative to the one or more support lines,
e) and effectively securing the shade lower support structure to the line or lines at a selected height position relative to the line length,
f) said securing including effecting adjustable wrapping of the line or lines about a rotary drum or drums provided and positioned at said lower support structure, to travel therewith,
g) whereby the height of the shade bottom can be quickly manually adjusted by adjustment of the height of the shade lower support structure.
As will appear, the shade is typically provided in the form of a sequence of pleats, and the line or lines is or are located adjacent such pleats.
Another object includes provision for weight of the lowermost extent of the shade to be carried by the shade lower support structure as that lower support structure is elevated to shorten the height of the shade. As the shade lower support structure is adjusted upwardly, the line below that support structure is typically wound automatically by a traveling drum or drums associated with and below the lowermost support structure.
A further object is to provide for encasing the drum or drums in a housing or housings, and supporting the shade lower support structure on the housing or housings.
The housings are typically located at laterally spaced locations and directly beneath or inside the lower support structure.
Another object includes provision of a spring or springs associated with the drum or drums, and acting to urge the drum or drums in rotary direction to automatically wind the line or lines.
A further object includes provision of a support shoulder on upper extent of, said housing or housings to engage lowermost surfaces of the lower support structure, and acting to orient said housing or housings relative to said shade support structure to enable line winding.
An additional object includes provision of a manipulable line gripping stop, in association with each housing, to grip the line in shade height adjusted position, and to loosen the line for winding or unwinding as the shade height is adjusted.